Device for truing brake drums



Nov. 17, 1931. c. v. CARLSON V 3 5 DEVICE FOR TRUING BRAKE DRUMS V FiledSept. 8, 1930 gwuc/Wbo Patented Nov. 17, 1931 PA'TENT OFFICE CHARLES V.CARLSON, OF LOS ANGELES, CALIFOBNIA i DEVICE FOR TRUING BRAKE DRUMSApplication fi1ed September 8, 1930. Serial No. 480,(189.

This invention aims to provide an improved and accurate means for truingbrake drums, by the use of a micrometer which is a 4 V part of thedevice. A further object of the !i invention is to supply a tool of theclass described provided with a spindle, or equivalent means, which,extending through the neck of the drum or through the wheel bearing,acts as a guide for the body portion of the devioe, thus eliminating allchance of error in straightening or truing drums. A further object ofthe invention is to provide a device of the class described which willoperate on any and all pressed drums, and will true them to within athousandth of an inch, without wealening the drum, it being unnecessaryto cut, grind, or otherwise remove any portion of the constituentmaterial of the rim of the drum. It is within the province of thedisclosure to improve generally, and to enhance the utility of devicesof that type to which the present invention appertains.

With the above and other objects in View which will appear as thedescription proceeds, the invention resides in the combination andarrangement of parte and in the details of Construction hereinafterdescribed and claimed, it being understood that changes in the preciseemhodiment of the invention herein clisclosed may be made within thescope of what is claimed without departin; from the spirit of theinvention.

In the accompanying drawings:

Figure 1 shows in elevation, a device constructed in accordance with theinvention, mounted within a rear brake drum, parts being in section;

Figure 2 is a section on the line 2-2 of 'f Figure 1 Figure 3 is asection on the line 3-3 of Figure 1; i

Figure i is a sectional View illustrating how the device may be used inconnection with a front wheel drum.

The device forming the subject matter of this application preferably ismade of niet-al throughout. It includes a disk-like body 1 of circularOutline. The body l is supplied at its center with a forwardly ex endedstem 2 carrying a turning handle or a knob 3 constituting means wherebythe body 1 may be rotated.

The body 1 is supplied with a rearwardly extended spindle 4, which isthreaded at its rear end, as shown at 5, to receive a nut 6. In the rearside of the body l there are oppositely disposed arcuate recesses 7, thespindle %i extending between them. The spindle 4 has a shoulder 8 whichis located near to the rear surface of the body 1, as F igure 3 willshow. i

A bushing 9 is slipped over the spindle 4, if the brake drum of a rearwheel is to be trued, as shown in Figures l, 2 and 3 of the drawings,the forward end ofthe bushing 9 extending into the recesses 7. Thebushin 9 is supplied with an internal shoulder iO which abuts againstthe shoulder 8 of the spindle 4:. i

. There are openings 11 through the body 1, on opposite sides of thestern 2. In its perphery, the body 1 has rectangular seats 12 in which"correspondingly shaped shoes 14 are mounted to move inwardly andoutwardly, in a radial direction, the outer edges of the shoes orexpansion members 14 being curved, as shown in Figure 1.

An Operating means for the shoes 14 is provided, and this meanspreferahly takes the i form of screws 15 threaded into the body 1, thescrews having heads 16 which are located in the openngs 11. The screws15 have smooth reducecl ends 17 which are journaled for rotation in theshoes 14, and are held therein at 18 for rotation.

In the forward side of the body 1, near to the edge thereof, there is adepresson 19 with which communicates an outwardly eX- tended slot 20. Amicrometer 21 is Secured in the depression 19 and includes a movablemember 22, extended outwardly through the slot 20 and having a tendencyto move outwardly in the direction of its length.

The numeral 23 marks a rear drum, including a rim 24 and a neck 25, thedrum having an internal recess 26. The bushing 9 is received in therecess 26, 'the spindle i extends outwardly through the neck 25 of thedrum, and the nut 6 is threaded on the end 5 of the spindle 4:, as shownin Figure 4, although Figure l illustrates a slightly differentapplication of the nventon from the one now under consideration. Thebody l is located within the rim 24 of the brake drum 23.

Assuming that the parts are located as saown in Figures 1 and 9, thebody l is rotated by means of the knob 3. The member 92 ot themicrometer 21 rdes on the inner surface of the rim 24 ot the brake drum,and the mierometer 91 thereby is caused to show where the rim of thedrum is out of true and how much it is out of true.

A wrench or the like, applied to the heads ot the screws 15, may be usedto rotate the screws, the screws 'orcing the shoes 14 outwardly, therebyshape those portions ot the rim 24 which the micrometer 21-22 has shownto be out ot' condition.

In the event thatthe device is to be used in connection with a frontwheel drum. as shown in Figure l, the hushng 9 is taken o't there beingno recess like the recess 26 ot' Fioure 2, in the front bralre drum 27of Fi zure 4-.

The deviee is se constructed that it will indicate where the drum is outot shane and how much it is out of shane: thereatter. by the simplemanipulation ot the screws 16. the shoes may he brought into pla torestore the rim of the drum to a true condition.

is to he observed that no turning of? of the rim 9 s reouired, in orderto true it, and, conseouently there is no less ot metal and noweelteninx; ot the rim ot the drum.

Having; th us described the nvention, What is claimed is:

1. In a de ice ot the class described. a body, means tor mourning' thebody tor rotation in a brake drum. outwardly actin measuring means atthe edge ot' the body, and outwardly actinr expansion means under thecontrol ot an operator and located atthe said edge of the body.

In a deyice ot' the class describech a body, means for mounting` thebody for rotation in a hrake drum. an outwardly acting micrometer at theedge of the body, an outwardly moyable Shoe at said edge of the body,and means under the control of an operator for actuating the shoe.

3. i devce of the class described, a body, means 'for mounting the bodyfor rotation in a breke drum, a shoe at the edge ot" the body, meansunder the control ot' an operator tor the shoe in and out, and an ndi. muns at said edge of the body.

de ice ot the class described, a body, e handle on the 'ront side of thebody, and eonstitutng means whereby the body may be rotated, a spindleon the back side ot the body and torming means whereby the body may bemounted tor rotaton in the brake drum, an indicating means carred at theedge of the CHARLES V. CAELSON.

